How to use dynamic variable names for tukey contrasts?

[Macondo_Cuanto]

I wrote a markdown report that uses hard-coded data and grouping variables. I'm trying to make it more flexible by using dynamic field names instead to avoid extensive find/replace editing when I process data with different headers.

Incorporating dynamic variable names in downstream functions has been challenging; I'm struggling to find a solution for functions bundled with the Multcomp package.

Would someone please demonstrate how to pass a dynamic field name into the glht function shown below?

Thank you.

#load library
library(multcomp)

#example data

my_data <- as.data.frame(HairEyeColor)

#setup group and data variables for use in other functions

group_var <- "Hair"

data_var <- "Freq"

#downstream ANOVA functions

anova <- aov(Freq ~ Hair, data = my_data) #hard-coded version  works

anova <- rlang::eval_tidy(rlang::expr(aov(!!as.symbol(data_var) ~ !!as.symbol(group_var), data = my_data))) 
#group_var works with helper functions


tukey <- glht(anova, linfct = mcp(Hair = "Tukey")) #hard-coded group works


tukey <- glht(anova, linfct = mcp(group_var = "Tukey")) #dynamic group_var doesn't work


tukey <- rlang::eval_tidy(rlang::expr(glht(anova, linfct = mcp(!!as.symbol(group_var) = "Tukey"))) #group_var doesn't work here, either

[Macondo_Cuanto]

I solved this by using the do.call() function.

tukey <- glht(anova, linfct = do.call(mcp, setNames(list("Tukey"), group_var)))